Asian Carp Foes Argue Before Federal Judge

In concentrated numbers, the leaping Asian carp pose significant danger to boaters navigating the open rivers. But from a purely ecological standpoint, the non-native carp feed primarily on plankton and bacteria, collapsing the food chain. (Credit: CBS)

The Battle Over The Asian Carp Enters The Final Stage

CHICAGO (CBS) – Attorneys for and against closing Chicago-area shipping locks as a way to stop the spread of Asian carp are now making their final pitches to a federal judge.

Oral arguments Monday are the last step before U.S. District Judge Robert Dow decides the issue.

Asian carp, which can weigh up to 100 pounds, have been migrating up the Mississippi and Illinois rivers toward the Great Lakes for decades.

The states Michigan, Minnesota, Ohio, Pennsylvania and Wisconsin say the action would ensure the invasive fish will not overrun the Great Lakes and devastate a $7 billion-a-year fishing industry. Michigan Attorney General Mike Cox filed the original lawsuit to close the O’Brien and Chicago locks on the Chicago Sanitary & Ship canal.

But the City of Chicago, barge companies and others counter that closing the locks would undermine flood-control measures and cost businesses billions.

Dow heard witness testimony in September. The states say carp could enter Lake Michigan from Chicago waterways at any time, so Dow could rule soon after oral arguments.

The U.S. Supreme Court has twice rejected state pleas to close the locks, but did not rule on the merits of the legal claims.

The flow of the Chicago River was reversed more than a century ago with the creation of the canal, in an effort to end the untreated dumping of waste into Lake Michigan, which is the area’s source of drinking water.

Despite the city’s official position, Mayor Richard M. Daley has suggested turning back the reversal, which has long been considered a great engineering feat.

“I said that’s a great project, we have to start thinking about it now, and of course go to the business community and set up a committee and work with Water Reclamation District and others and Army Corps of Engineers,” Daley told the Chicago Tribune last month. “That could be the salvation maybe of the Great Lakes.”